Drill versus Metal- Japanese TV

[cloa]

This a regular event between reputable manufacturer. I am still searching for the video but basically from I saw its was a tungsten carbide drill versus a non-composite metal plate. 2 hours after starting with copious amounts of coolant, the drill break through without splitting the metal. Does a challenge like this serve any purpose? Maybe frustrating bank robbers but they'd use plasma or water cutting- not wait two hours to cut into a safe and it was fully enclosed and automated drill- not a portable device.

http://www.eng-tips.com/threadminder.cfm?pid=1529

Use translation assistance for Engineers forum

Note the rules include No Student posting

 

[MikeHalloran]

I set up a CNC horizontal mill to cut a 1-5/8" dia hole through 2" of 2024-T3 aluminum, using a two-flute carbide insert drill. At 3500 rpm, the cycle pushed the 10 HP spindle to 13 HP, which was okay with the mill mfgr because the cut only took 6 seconds. The part I liked was that some of the chips bounced off a 20 ft. ceiling and fell outside the mill's splash shield.


I'm wondering what material was being cut in the show you watched. .. because I'm having a hard time imagining carbide taking two hours to cut through a reasonable thickness of anything that it can scratch.


Mike Halloran
Pembroke Pines, FL, USA

 

[cloa]

I think they were taking the cutting very slowly to avoid splitting the specified small plate of metal- a previous time was draw because they penetrated but the plate split. An inch thick special metal.

http://www.eng-tips.com/threadminder.cfm?pid=1529

Use translation assistance for Engineers forum

Note the rules include No Student posting

 

[cloa]

http://www.dailymotion.com/video/x150zly_ほこ-たて-130922-ドリルｖｓ金属-第７弾_shortfilms

http://www.eng-tips.com/threadminder.cfm?pid=1529

Use translation assistance for Engineers forum

Note the rules include No Student posting

 

[MikeHalloran]

Ah.

The square workpiece that shatters as they press a (possibly nonrotating) rod into it is probably tungsten carbide. It's rather glass-like under load, especially any situation that stresses it in tension.

Most of the fuss in the film seems to be about some grinding pins that they use to plunge into the carbide (while they are rotating) to make blind holes.

The pins are unusual in several respects. The film shows, briefly, a plunge EDM machine cutting one of the paraxial holes that are then filled with ... something. There are also radial holes, also filled with ... something.

I'm not clear on the function of the paraxial holes (except the center one) or the radial holes. Note that they are not visible in the finished product, which has been coated with abrasive (probably diamond) flakes.

I'm a little puzzled about the core material.
The abrasive flakes could be 'set' individually, as is common in diamond tooling, if the pins are somewhat ductile, like steel. But then there would be no reason to EDM the axial and radial holes for the ... dampers?

Anyway, yes it could take and hour or two to plunge a hole through a piece of carbide with a grinding pin. They are definitely not hogging those holes with carbide cutting tools.




Mike Halloran
Pembroke Pines, FL, USA

 

[cloa]

Engineering challenges can produced useful side benefits such as solar car challenges producing aerodynamic improvements for normal car; small rockets offering benefits for their full size equivalent, one-off grand civil engineering project producing logistically and techniques for other project. Does this one have an foreseeable benefits to engineering?

http://www.eng-tips.com/threadminder.cfm?pid=1529

Use translation assistance for Engineers forum

Note the rules include No Student posting

 

[MikeHalloran]

Plunge grinding with abrasive pins is old tech, but evolution continues.
I'm very curious about those inserted radial and paraxial whatevers that are concealed by the abrasive in the finished product. I'm guessing they improve vibration response, or heat transfer, or ... something. Maybe they'll hit the market here and get some English copy so we can find out what all the fuss is about.

Improvements to individual devices produce evolutionary changes in a wider scope of products only after they are published or otherwise revealed.

Example:
When Mark Donohue was racing Camaros for Roger Penske, they were going to a lot of trouble to fit the door glass nearly flush to the body. ... and winning races. Flush-ish door glass didn't make it into production cars until decades later; now it's almost universal.

I'm also convinced that the beautiful metallic blue paint on Penske's Camaros was really just a thin wash, applied fresh every week, after heavily sanding the entire exterior of the car whether it had been damaged or not, so not only did they save weight by not using primer or multiple coats of paint, but the body panels got progressively thinner and lighter as the season wore on.



Mike Halloran
Pembroke Pines, FL, USA

 

[cloa]

Does it serve any purpose to develop such a metal plate? I imagine a nondrillable metal would heterogeneous horizontally especially with irregular hard precipitates so the drill would have to keep slowing down and speeding up to effectively cut.

http://www.eng-tips.com/threadminder.cfm?pid=1529

Use translation assistance for Engineers forum

Note the rules include No Student posting

 

[MikeHalloran]

The metal plate that Nippon Carbide is cutting in the film is most likely tungsten carbide.
"Irregular hard precipitates" is a halfway decent description of tungsten carbide, which actually comprises very small particles of tungsten carbide in a metallic binder, e.g. (I think) nickel and/or cobalt.
It is very definitely not machinable in any normal sense, and must be shaped by grinding, with a really really hard grit, like diamond.
The film seems to be a publicity piece for a new type of abrasive grinding pin.

Any improvement in the cost and/or speed capability of such abrasive tools is of great commercial importance, not just in production of carbide parts, but in production of things like ceramic knives and ceramic armor.




Mike Halloran
Pembroke Pines, FL, USA

 

[cloa]

This challenge has been running for a long time- I saw it last year and the year before. Just like in English, the name for a ceramic composite (cermet) in Japanese is　サーメット　(saametto). Of course just about every engineering alloys is really a composite to some degree but calling tungsten carbide in a nickel matrix is bit of stretch. Also don't they usually aim for uniform distribution- if it needs machining its difficult enough without the ceramics/precipitates being clustered. I have never seen WC-Ni as a plate before. Does 2 hours seem like a speed improvement?

http://www.eng-tips.com/threadminder.cfm?pid=1529

Use translation assistance for Engineers forum

Note the rules include No Student posting

 

[MikeHalloran]

Putting a big hole in a thick blank of Ni could take a couple of hours; it's hard stuff.
WC is even harder, but I'm not sure it's even possible to produce it in sheet/plate/bulk form.
All of the 'WC' I've ever heard of or worked with is really WC powder in some kind of matrix.



Mike Halloran
Pembroke Pines, FL, USA

 

[looslib]

Penske used to acid-dip the Camaro bodies to about half the normal metal thickness. The 1969 Camaros with the 'vinyl roofs' was done to camoflauge the roof being too thin and was rippled, so they covered it. When the SCCA ordered them to remove the vinyl covering, they found it easier to cut the roof off and weld on a new one.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli